Fuel compositions containing substituted poly(oxyalkylene) aromatic ethers

ABSTRACT

A fuel additive having the formula: ##STR1## where A 1  is a thioether, a sulfoxide, a sulfone, a sulfonic acid, a sulfonamide, a nitrile, a carboxylic acid or ester, or a carboxamide; R 1  and R 2  are independently hydrogen, hydroxy, lower alkyl, or lower alkoxy; R 3  and R 4  are independently hydrogen or lower alkyl and each R 3  and R 4  is independently selected in each --O--CHR 3  --CHR 4  -- unit; R 5  is hydrogen, alkyl having 1 to 100 carbon atoms, phenyl, aralkyl having 7 to 100 carbon atoms or alkaryl having 7 to 100 carbon atoms, or an acyl group of the formula: ##STR2## where R 6  is alkyl having 1 to 30 carbon atoms, phenyl, aralkyl having 7 to 36 carbon atoms or alkaryl having 7 to 36 carbon atoms; n is an integer from 5 to 100; and x is an integer from 0 to 10.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to poly(oxyalkylene) aromatic ethers and to fuelcompositions containing poly(oxyalkylene) aromatic ethers. Moreparticularly, this invention relates to poly(oxyalkylene) aromaticethers which are substituted on the aromatic moiety and to the use ofsuch compounds in fuel compositions to prevent and control enginedeposits.

2. Description of the Related Art

It is well known that automobile engines tend to form deposits on thesurface of engine components, such as carburetor ports, throttle bodies,fuel injectors, intake ports and intake valves, due to the oxidation andpolymerization of hydrocarbon fuel. These deposits, even when present inrelatively minor amounts, often cause noticeable driveability problems,such as stalling and poor acceleration. Moreover, engine deposits cansignificantly increase an automobile's fuel consumption and productionof exhaust pollutants. Therefore, the development of effective fueldetergents or "deposit control" additives to prevent or control suchdeposits is of considerable importance and numerous such materials areknown in the art.

For example, aliphatic hydrocarbon-substituted phenols are known toreduce engine deposits when used in fuel compositions. U.S. Pat. No.3,849,085, issued Nov. 19, 1974 to Kreuz et al., discloses a motor fuelcomposition comprising a mixture of hydrocarbons in the gasoline boilingrange containing about 0.01 to 0.25 volume percent of a high molecularweight aliphatic hydrocarbon-substituted phenol in which the aliphatichydrocarbon radical has an average molecular weight in the range ofabout 500 to 3,500. This patent teaches that gasoline compositionscontaining minor amounts of an aliphatic hydrocarbon-substituted phenolnot only prevent or inhibit the formation of intake valve and portdeposits in a gasoline engine, but also enhance the performance of thefuel composition in engines designed to operate at higher operatingtemperatures with a minimum of decomposition and deposit formation inthe manifold of the engine.

Similarly, U.S. Pat. No. 4,134,846, issued Jan. 16, 1979 to Machleder etal., discloses a fuel additive composition comprising a mixture of (1)the reaction product of an aliphatic hydrocarbon-substituted phenol,epichlorohydrin and a primary or secondary mono- or polyamine, and (2) apolyalkylene phenol. This patent teaches that such compositions showexcellent carburetor, induction system and combustion chamber detergencyand, in addition, provide effective rust inhibition when used inhydrocarbon fuels at low concentrations.

Amino phenols are also known to function as detergents/dispersants,antioxidants and anti-corrosion agents when used in fuel compositions.U.S. Pat. No. 4,320,021, issued Mar. 16, 1982 to R. M. Lange, forexample, discloses amino phenols having at least one substantiallysaturated hydrocarbon-based substituent of at least 30 carbon atoms. Theamino phenols of this patent are taught to impart useful and desirableproperties to oil-based lubricants and normally liquid fuels. Similaramino phenols are disclosed in related U.S. Pat. No. 4,320,020, issuedMar. 16, 1982 to R. M. Lange.

Similarly, U.S. Pat. No. 3,149,933, issued Sep. 22, 1964 to K. Ley etal., discloses hydrocarbon-substituted amino phenols as stabilizers forliquid fuels.

U.S. Pat. No. 4,386,939, issued Jun. 7, 1983 to R. M. Lange, disclosesnitrogen-containing compositions prepared by reacting an amino phenolwith at least one 3- or 4-membered ring heterocyclic compound in whichthe hetero atom is a single oxygen, sulfur or nitrogen atom, such asethylene oxide. The nitrogen-containing compositions of this patent aretaught to be useful as additives for lubricants and fuels.

Nitro phenols have also been employed as fuel additives. For example,U.S. Pat. No. 4,347,148, issued Aug. 31, 1982 to K. E. Davis, disclosesnitro phenols containing at least one aliphatic substituent having atleast about 40 carbon atoms. The nitro phenols of this patent are taughtto be useful as detergents, dispersants, antioxidants and demulsifiersfor lubricating oil and fuel compositions.

Similarly, U.S. Pat. No. 3,434,814, issued Mar. 25, 1969 to M. Dubeck etal., discloses a liquid hydrocarbon fuel composition containing a majorquantity of a liquid hydrocarbon of the gasoline boiling range and aminor amount sufficient to reduce exhaust emissions and engine depositsof an aromatic nitro compound having an alkyl, aryl, aralkyl,alkanoyloxy, alkoxy, hydroxy or halogen substituent.

Fuel additives containing a poly(oxyalkylene) moiety are also known inthe art. For example, U.S. Pat. No. 4,191,537, issued Mar. 4, 1980 to R.A. Lewis et al., discloses a fuel composition comprising a major portionof hydrocarbons boiling in the gasoline range and from 30 to 2000 ppm ofa hydrocarbyl poly(oxyalkylene) aminocarbamate having a molecular weightfrom about 600 to 10,000, and at least one basic nitrogen atom. Thehydrocarbyl poly(oxyalkylene) moiety is composed of oxyalkylene unitsselected from 2 to 5 carbon oxyalkylene units. These fuel compositionsare taught to maintain the cleanliness of intake systems withoutcontributing to combustion chamber deposits.

Aromatic compounds containing a poly(oxyalkylene) moiety are also knownin the art. For example, the above-mentioned U.S. Pat. No. 4,191,537,discloses alkylphenyl poly(oxyalkylene) polymers which are useful asintermediates in the preparation of alkylphenyl poly(oxyalkylene)aminocarbamates.

Similarly, U.S. Pat. No. 5,090,914, issued Feb. 25, 1992 to D. T.Reardan et al., discloses poly(oxyalkylene) aromatic compounds having anamino or hydrazinocarbonyl substituent on the aromatic moiety and anester, amide, carbamate, urea or ether linking group between thearomatic moiety and the poly(oxyalkylene) moiety. These compounds aretaught to be useful for modifying macromolecular species such asproteins and enzymes. U.S. Pat. Nos. 5,081,295; 5,103,039; and5,157,099; all issued to D. T. Reardan et al., disclose similarpoly(oxyalkylene) aromatic compounds.

In addition, U.S. Pat. No. 4,231,759, issued Nov. 4, 1980 to Udelhofenet al., discloses a fuel additive composition comprising the Mannichcondensation product of (1) a high molecular weight alkyl-substitutedhydroxyaromatic compound wherein the alkyl group has a number averagemolecular weight of about 600 to about 3,000, (2) an amine, and (3) analdehyde. This patent teaches that such Mannich condensation productsprovide carburetor cleanliness when employed alone, and intake valvecleanliness when employed in combination with a hydrocarbon carrierfluid.

U.S. Pat. No. 4,859,210, issued Aug. 22, 1989 to Franz et al., disclosesfuel compositions containing (1) one or more polybutyl or polyisobutylalcohols wherein the polybutyl or polyisobutyl group has a numberaverage molecular weight of 324 to 3,000, or (2) a poly(alkoxylate) ofthe polybutyl or polyisobutyl alcohol, or (3) a carboxylate ester of thepolybutyl or polyisobutyl alcohol. This patent further teaches that whenthe fuel composition contains an ester of a polybutyl or polyisobutylalcohol, the ester-forming acid group may be derived from saturated orunsaturated, aliphatic or aromatic, acyclic or cyclic mono- orpolycarboxylic acids.

U.S. Pat. No. 3,285,855, issued Nov. 15, 1966 to Dexter et al.,discloses alkyl esters of dialkyl hydroxybenzoic andhydroxyphenylalkanoic acids wherein the ester moiety contains from 6 to30 carbon atoms. This patent teaches that such esters are useful forstabilizing polypropylene and other organic material normally subject tooxidative deterioration. Similar alkyl esters containing hindereddialkyl hydroxyphenyl groups are disclosed in U.S. Pat. No. 5,196,565,which issued Mar. 23, 1993 to Ross.

U.S. Pat. No. 5,196,142, issued Mar. 23, 1993 to Mollet et al.,discloses alkyl esters of hydroxyphenyl carboxylic acids wherein theester moiety may contain up to 23 carbon atoms. This patent teaches thatsuch compounds are useful as antioxidants for stabilizingemulsion-polymerized polymers.

It has now been discovered that certain poly(oxyalkylene) aromaticethers which are substituted on the aromatic moiety are surprisinglyuseful for reducing engine deposits, especially intake valve deposits,when employed as fuel additives in fuel compositions.

SUMMARY OF THE INVENTION

The present invention provides novel substituted poly(oxyalkylene)aromatic ethers which are useful as fuel additives for the preventionand control of engine deposits, particularly intake valve deposits.

The substituted poly(oxyalkylene) aromatic ethers of the presentinvention have the formula: ##STR3## wherein A₁ is selected from thegroup consisting of SR^(I), SOR^(II), SO₂ R^(III), wherein R^(I), R^(II)and R^(III) are independently lower alkyl of 1 to 6 carbon atoms; SO₃ H;SO₂ NR^(IV) R^(V), wherein R^(IV) and R^(V) are independently hydrogen,lower alkyl of 1 to 6 carbon atoms, or aminoalkyl of 1 to 6 carbonatoms, provided that R^(IV) and R^(V) may not both be aminoalkyl; CN;CO₂ R^(VI), wherein R^(VI) is hydrogen or lower alkyl of 1 to 6 carbonatoms; and C(O)NR^(VII) R^(VIII), wherein R^(VII) and R^(VIII) areindependently hydrogen, lower alkyl of 1 to 6 carbon atoms or aminoalkylof 1 to 6 carbon atoms, provided that R^(VII) and R^(VIII) may not bothby aminoalkyl;

R_(l) and R₂ are independently hydrogen, hydroxy, lower alkyl having 1to 6 carbon atoms, or lower alkoxy having 1 to 6 carbon atoms; R₃ and R₄are independently hydrogen or lower alkyl having 1 to 6 carbon atoms andeach R₃ and R₄ is independently selected in each --O--CHR₃ --CHR₄ --unit; R₅ is hydrogen, alkyl having 1 to 100 carbon atoms, phenyl,aralkyl having 7 to 100 carbon atoms or alkaryl having 7 to 100 carbonatoms, or an acyl group of the formula: ##STR4## wherein R₆ is alkylhaving 1 to 30 carbon atoms, phenyl, aralkyl having 7 to 36 carbon atomsor alkaryl having 7 to 36 carbon atoms; n is an integer from 5 to 100;and x is an integer from 0 to 10.

The present invention further provides a fuel composition comprising amajor amount of hydrocarbons boiling in the gasoline or diesel range andan effective deposit-controlling amount of a substitutedpoly(oxyalkylene) aromatic ether of the present invention.

The present invention additionally provides a fuel concentratecomprising an inert stable oleophilic organic solvent boiling in therange of from about 150° F. (65° C.) to 400° F. (205° C.) and from about10 to 70 weight percent of a substituted poly(oxyalkylene) aromaticether of the present invention.

Among other factors, the present invention is based on the discoverythat certain poly(oxyalkylene) aromatic ethers which are substituted onthe aromatic moiety are surprisingly useful for reducing enginedeposits, especially on intake valves, when employed as fuel additivesin fuel compositions.

DETAILED DESCRIPTION OF THE INVENTION

The fuel additives provided by the present invention have the generalformula: ##STR5## wherein A₁, R₁, R₂, R₃, R₄, R₅, n and x are as definedabove.

In formula I, above, A₁ may be a thioether, SR^(I), a sulfoxide,SOR^(II), a sulfone, SO₂ R^(III), a sulfonic acid, SO₃ H, a sulfonamide,SO₂ NR^(IV) R^(V), a nitrile(cyano), CN, a carboxylic acid or ester, CO₂R^(VI), or a carboxamide, C(O)NR^(VII) R^(VIII).

Preferably, A₁ is a thioether, SR^(I), a sulfone, SO₂ R^(III), anitrile, CN, a carboxylic acid or ester, CO₂ R^(VI), or a carboxamide,C(O)NR^(VII) R^(VIII). More preferably, A₁ is a thioether, SR^(I), asulfone, SO₂ R^(III), or a nitrile, CN.

Preferably, R₁ is hydrogen, hydroxy, or lower alkyl having 1 to 4 carbonatoms. More preferably, R₁ is hydrogen or hydroxy. Most preferably, R₁is hydrogen.

R₂ is preferably hydrogen.

Preferably, one of R₃ and R₄ is lower alkyl having 1 to 3 carbon atomsand the other is hydrogen. More preferably, one of R₃ and R₄ is methylor ethyl and the other is hydrogen. Most preferably, one of R₃ and R₄ isethyl and the other is hydrogen.

R₅ is preferably hydrogen, alkyl having 1 to 30 carbon atoms, oralkylphenyl having an alkyl group containing 1 to 30 carbon atoms. Morepreferably, R₅ is hydrogen, alkyl having 2 to 24 carbon atoms, oralkylphenyl having an alkyl group containing 2 to 24 carbon atoms. Stillmore preferably, R₅ is hydrogen, alkyl having 4 to 12 carbon atoms oralkylphenyl having an alkyl group containing 4 to 12 carbon atoms. Mostpreferably, R₅ is alkylphenyl having an alkyl group containing 4 to 12carbon atoms.

R₆ is preferably alkyl having 4 to 12 carbon atoms.

Preferably, n is an integer from 8 to 50. More preferably, n is aninteger from 10 to 30. Preferably, x is an integer from 0 to 2. Mostpreferably, x is 0.

A preferred group of substituted poly(oxyalkylene) aromatic ethers ofthe invention are compounds of formula I wherein R₁ is hydrogen orhydroxy; R₂ is hydrogen; one of R₃ and R₄ is hydrogen and the other ismethyl or ethyl; R₅ is hydrogen, alkyl having 1 to about 30 carbon atomsor alkylphenyl having an alkyl group containing 1 to about 30 carbonatoms; n is 8 to 50 and x is 0, 1 or 2.

A more preferred group of substituted poly(oxyalkylene) aromatic ethersare those of formula I wherein R₁ is hydrogen or hydroxy; R₂ ishydrogen; one of R₃ and R₄ is hydrogen and the other is methyl or ethyl;R₅ is hydrogen, alkyl having 2 to 24 carbon atoms or alkylphenyl havingan alkyl group containing 2 to 24 carbon atoms; n is 8 to 50; and x is0.

It is especially preferred that the A₁ substituent present in thearomatic moiety of the poly(oxyalkylene) aromatic ethers of thisinvention be situated in a meta or para position relative to thepoly(oxyalkylene) ether moiety. When the aromatic moiety also contains ahydroxyl substituent, it is particularly preferred that this hydroxylgroup be in a meta or para position relative to the poly(oxyalkylene)ether moiety and in an ortho position relative to the A₁ substituent.

The poly(oxyalkylene) aromatic ethers employed in the present inventionwill generally have a sufficient molecular weight so as to benon-volatile at normal engine intake valve operating temperatures (about200°-250° C.). Typically, the molecular weight of the poly(oxyalkylene)aromatic ethers will range from about 600 to about 10,000, preferablyfrom about 1,000 to 3,000.

Generally, the poly(oxyalkylene) aromatic ethers employed in thisinvention will contain an average of about 5 to about 100 oxyalkyleneunits; preferably, 8 to 50 oxyalkylene units; more preferably, 10 to 30oxyalkylene units.

Fuel-soluble salts of the poly(oxyalkylene) aromatic ethers of thepresent invention can be readily prepared for those compounds containingan amino group and such salts are contemplated to be useful forpreventing or controlling engine deposits. Suitable salts include, forexample, those obtained by protonating the amino moiety with a strongorganic acid, such as an alkyl- or arylsulfonic acid. Preferred saltsare derived from toluenesulfonic acid and methanesulfonic acid.

Definitions

As used herein, the following terms have the following meanings unlessexpressly stated to the contrary.

The term "amino" refers to the group: --NH₂.

The term "alkyl" refers to both straight- and branched-chain alkylgroups.

The term "lower alkyl" refers to alkyl groups having 1 to about 6 carbonatoms and includes primary, secondary and tertiary alkyl groups. Typicallower alkyl groups include, for example, methyl, ethyl, n-propyl,isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, n-hexyl and the like.

The term "lower alkoxy" refers to the group --OR_(d) wherein R_(d) islower alkyl. Typical lower alkoxy groups include methoxy, ethoxy, andthe like.

The term "alkaryl" refers to the group: ##STR6## wherein R_(e) and R_(f)are each independently hydrogen or an alkyl group, with the proviso thatboth R_(e) and R_(f) are not hydrogen. Typical alkaryl groups include,for example, tolyl, xylyl, cumenyl, ethylphenyl, butylphenyl,dibutylphenyl, hexylphenyl, octylphenyl, dioctylphenyl, nonylphenyl,decylphenyl, didecylphenyl, dodecylphenyl, hexadecylphenyl,octadecylphenyl, icosylphenyl, tricontylphenyl and the like. The term"alkylphenyl" refers to an alkaryl group of the above formula in whichR_(e) is alkyl and R_(f) is hydrogen.

The term "aralkyl" refers to the group: ##STR7## wherein R_(g) and R_(h)are each independently hydrogen or an alkyl group; and R_(i) is analkylene group. Typical alkaryl groups include, for example, benzyl,methylbenzyl, dimethylbenzyl, phenethyl, and the like.

The term "oxyalkylene unit" refers to an ether moiety having the generalformula: ##STR8## wherein R_(j) and R_(k) are each independentlyhydrogen or lower alkyl groups.

The term "poly(oxyalkylene)" refers to a polymer or oligomer having thegeneral formula: ##STR9## wherein R_(j) and R_(k) are as defined above,and z is an integer greater than 1. When referring herein to the numberof poly(oxyalkylene) units in a particular poly(oxyalkylene) compound,it is to be understood that this number refers to the average number ofpoly(oxyalkylene) units in such compounds unless expressly stated to thecontrary.

General Synthetic Procedures

The poly(oxyalkylene) aromatic ethers of the present invention can beprepared by the following general methods and procedures. Those skilledin the art will recognize that where typical or preferred processconditions (e.g., reaction temperatures, times, mole ratios ofreactants, solvents, pressures, etc.) are given, other processconditions may also be used unless otherwise stated. Optimum reactionconditions may vary with the particular reactants or solvents used, butone skilled in the art will be able to determine such conditions byroutine optimization procedures.

Moreover, those skilled in the art will recognize that it may benecessary to block or protect certain functional groups while conductingthe following synthetic procedures. In such cases, the protecting groupwill serve to protect the functional group from undesired reactions orto block its undesired reaction with other functional groups or with thereagents used to carry out the desired chemical transformations. Theproper choice of a protecting group for a particular functional groupwill be readily apparent to one skilled in the art. Various protectinggroups and their introduction and removal are described, for example, inT. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis,Second Edition, Wiley, N.Y., 1991, and references cited therein.

In the present synthetic procedures, a hydroxyl group, if present, willpreferably be protected, when necessary, as the benzyl ortert-butyldimethylsilyl ether. Introduction and removal of theseprotecting groups is well described in the art.

The poly(oxyalkylene) aromatic ethers of the present invention may beprepared from an aromatic compound having the formula: ##STR10## whereinA₁, R₁, R₂, and x are as defined above.

The aromatic compounds of formula III are either known compounds or canbe prepared from known compounds by conventional procedures. Aromaticcompounds suitable for use as starting materials in this inventioninclude, for example, 4-methylmercaptophenol, 4-cyanophenol,4-hydroxybenzamide, tert-butyl-4-hydroxybenzoate, and the like.

Preferred aromatic compounds of formula III include4-methylmercaptophenol and 4-cyanophenol.

Alternatively, substituent A₁ can be further modified by conventionalprocedures well known to those skilled in the art to provide additionalaromatic compounds encompassed by formula III, above.

In a preferred method of synthesizing the poly(oxyalkylene) aromaticethers of the present invention, an aromatic compound of formula III isdeprotonated with a suitable base to provide a metal salt having theformula: ##STR11## wherein A₁, R₁, R₂ and x are as defined above; and Mis a metal cation, such as lithium, sodium or potassium.

Generally, this deprotonation reaction will be effected by contactingIII with a strong base, such as sodium hydride, potassium hydride,sodium amide and the like, in an inert solvent, such as toluene, xyleneand the like, under substantially anhydrous conditions at a temperaturein the range from about -10° C. to about 120° C. for about 0.25 to about3 hours.

Metal salt IV is generally not isolated, but is reacted in situ with apoly(oxyalkylene) derivative having the formula: ##STR12## wherein R₃,R₄, n and x are as defined above, R₉ is an alkyl, phenyl, aralkyl oralkaryl group, and W is a suitable leaving group, such as a sulfonate ora halide, to provide a poly(oxyalkylene) aromatic ether of the formula:##STR13## wherein A₁, R₁ -R₄, R₉, n and x are as defined above.

Generally, this reaction will be conducted by contacting V with 0.8 to 5molar equivalents of IV in an inert solvent, such as toluene,tetrahydrofuran and the like, under substantially anhydrous conditionsat a temperature in the range of about 25° C. to about 150° C. for about1 to about 48 hours.

The poly(oxyalkylene) derivative V may be derived from apoly(oxyalkylene) alcohol having the formula: ##STR14## wherein R₃, R₄,R₉, n and x are as defined above.

The hydroxyl group of the poly(oxyalkylene) moiety of VII may beconverted into a suitable leaving group by contacting VII with asulfonyl chloride to form a sulfonate ester, such as a methanesulfonate(mesylate) or a toluenesulfonate (tosylate). Typically, this reaction isconducted in the presence of a suitable amine, such as triethylamine orpyridine, in an inert solvent, such as dichloromethane, at a temperaturein the range of about -10° C. to about 30° C. Alternatively, thehydroxyl group of the poly(oxyalkylene) moiety of VII can be exchangedfor a halide, such chloride or bromide, by contacting VII with ahalogenating agent, such as thionyl chloride, oxalyl chloride orphosphorus tribromide. Other suitable methods for preparing sulfonatesand halides from alcohols, and appropriate reaction conditions for suchreactions, can be found, for example, in I. T. Harrison and S. Harrison,Compendium of Organic Synthetic Methods, Vol. 1, pp. 331-337,Wiley-Interscience, New York (1971) and references cited therein.

The poly(oxyalkylene) alcohols of formula VII are known compounds thatcan be prepared using conventional procedures. For example, suitableprocedures for preparing such compounds are taught in U.S. Pat. Nos.2,782,240 and 02 2,841,479, the disclosures of which are incorporatedherein by reference.

Preferably, the poly(oxyalkylene) alcohols of formula V are prepared bycontacting an alkoxide or phenoxide metal salt having the formula:

    R.sub.9 OM                                                 (VIII)

wherein R₉ is as defined above and M is a metal cation, such as lithium,sodium, potassium and the like, with about 5 to about 100 molarequivalents of an alkylene oxide (an epoxide) having the formula:##STR15## wherein R₃ and R₄ are as defined above.

Typically, metal salt VIII is prepared by contacting the correspondinghydroxy compound R₉ OH with a strong base, such as sodium hydride,potassium hydride, sodium amide and the like, in an inert solvent, suchas toluene, xylene and the like, under substantially anhydrousconditions at a temperature in the range from about -10° C. to about120° C. for about 0.25 to about 3 hours.

Metal salt VIII is generally not isolated, but is reacted in situ withalkylene oxide IX to provide, after neutralization, thepoly(oxyalkylene) alcohol VII. This polymerization reaction is typicallyconducted in a substantially anhydrous inert solvent at a temperature ofabout 30° C. to about 150° C. for about 2 to about 120 hours. Suitablesolvents for this reaction, include toluene, xylene and the like.Typically, the reaction is conducted at a pressure sufficient to containthe reactants and the solvent, preferably at atmospheric or ambientpressure.

The amount of alkylene oxide employed in this reaction will generallydepend on the number of oxyalkylene units desired in the product.Typically, the molar ratio of alkylene oxide IX to metal salt VIII willrange from about 5:1 to about 100:1; preferably, from 8:1 to 50:1, morepreferably from 10:1 to 30:1.

Alkylene oxides suitable for use in this polymerization reactioninclude, for example, ethylene oxide; propylene oxide; butylene oxides,such as 1,2-butylene oxide (1,2-epoxybutane) and 2,3-butylene oxide(2,3-epoxybutane); pentylene oxides; hexylene oxides; octylene oxidesand the like. Preferred alkylene oxides are propylene oxide and1,2-butylene oxide.

In the polymerization reaction, a single type of alkylene oxide may beemployed, e.g., propylene oxide, in which case the product is ahomopolymer, e.g., a poly(oxypropylene) polymer. Copolymers are equallysatisfactory and random copolymers can be prepared by contacting metalsalt VI with a mixture of alkylene oxides, such as a mixture ofpropylene oxide and 1,2-butylene oxide, under polymerization conditions.Copolymers containing blocks of oxyalkylene units are also suitable foruse in this invention. Block copolymers can be prepared by contactingmetal salt VI with first one alkylene oxide, then others in any order,or repetitively, under polymerization conditions.

Poly(oxyalkylene) copolymers prepared by terminating or capping thepoly(oxyalkylene) moiety with 1 to 10 oxyethylene units, preferably. 2to 5 oxyethylene units, are particularly useful in the presentinvention, since these copolymers have been found to be more readilyconverted into an aromatic ether than those having an alkyl branch inthe terminal oxyalkylene unit. These copolymers may be prepared bycontacting metal salt VIII with an alkylene oxide of formula IX, such as1,2-butylene oxide or propylene oxide, under polymerization conditionsand then capping or terminating the resulting block of oxyalkylene unitswith oxyethylene units by adding ethylene oxide.

The poly(oxyalkylene) alcohol VII may also be prepared by living orimmortal polymerization as described by S. Inoue and T. Aida inEncyclopedia of Polymer Science and Engineering, Second Edition,Supplemental Volume, J. Wiley and Sons, New York, pages 412-420 (1989).These procedures are especially useful for preparing poly(oxyalkylene)alcohols of formula VII in which R₃ and R₄ are both alkyl groups.

As noted above, the alkoxide or phenoxide metal salt VIII used in theabove procedures is generally derived from the corresponding hydroxycompound, R₉ OH. Suitable hydroxy compounds include straight- orbranched-chain aliphatic alcohols having 1 to about 100 carbon atoms andphenols having the formula: ##STR16## wherein R₁₀ is an alkyl grouphaving 1 to about 100 carbon atoms and R₁₁ is hydrogen; or R₁₀ and R₁₁are both alkyl groups, each independently containing 1 to about 50carbon atoms.

Representative examples of straight- or branched-chain aliphaticalcohols suitable for use in this invention include, but are not limitedto, n-butanol; isobutanol; sec-butanol; t-butanol; n-pentanol;n-hexanol; n-heptanol; n-octanol; isooctanol; n-nonanol; n-decanol;n-dodecanol; n-hexadecanol (cetyl alcohol); n-octadecanol (stearylalcohol); alcohols derived from linear C₁₀ to C₃₀ alpha olefins andmixtures thereof; and alcohols derived from polymers of C₂ to C₆olefins, such as alcohols derived from polypropylene and polybutene,including polypropylene alcohols having 9 to about 100 carbon atoms andpolybutylene alcohols having 12 to about 100 carbon atoms. Preferredstraight- or branched-chain aliphatic alcohols will contain 1 to about30 carbon atoms, more preferably 2 to about 24 carbon atoms, and mostpreferably 4 to 12 carbon atoms. Particularly, preferred aliphaticalcohols are butanols.

The phenols of formula X may be monoalkyl-substituted phenols ordialkyl-substituted phenols. Monoalkyl-substituted phenols arepreferred, especially monoalkylphenols having an alkyl substituent inthe para position.

Preferably, the alkyl group of the alkylphenol will contain 1 to about30 carbon atoms, more preferably 2 to 24 carbon atoms, and mostpreferably 4 to 12 carbon atoms. Representative examples of phenolssuitable for use in this invention include, but are not limited to,phenol, methylphenol, dimethylphenol, ethylphenol, butylphenol,octylphenol, decylphenol, dodecylphenol, tetradecylphenol,hexadecylphenol, octadecylphenol, eicosylphenol, tetracosylphenol,hexacosylphenol, triacontylphenol and the like. Also, mixtures ofalkylphenols may be employed, such as a mixture of C₁₄ -C₁₈alkylphenols, a mixture of C₁₈ -C₂₄ alkylphenols, a mixture of C₂₀ -C₂₄alkylphenols, or a mixture of C₁₆ -C₂₆ alkylphenols.

Particularly, preferred alkylphenols are prepared by alkylating phenolwith polymers or oligomers of C₃ to C₆ olefins, such as polypropylene orpolybutene. These polymers typically contain 8 to about 100 carbonatoms, preferably 10 to 30 carbon atoms. An especially preferredalkylphenol is prepared by alkylating phenol with a propylene polymerhaving an average of 4 units. This polymer has the common name ofpropylene tetramer and is commercially available.

The poly ( oxyalkylene ) aromatic ethers of formula I wherein R₅ ishydrogen, i.e., compounds having the formula: ##STR17## wherein A₁, R₁-R₄, n and x are as defined above, may be prepared from compounds offormula VI wherein R₉ is a labile hydrocarbyl group, such as a benzyl ort-butyl group, by removing the hydrocarbyl group under appropriateconditions to provide a hydroxyl group. For example, compounds offormula VI where R₉ represents a benzyl group may be prepared byemploying a metal salt VIII derived from benzyl alcohol in theabove-described synthetic procedures. Cleavage of the benzyl ether usingconventional hydrogenolysis procedures then provides a compound offormula XI. Other labile hydrocarbyl groups, such as a t-butyl group,may be similarly employed for those compounds having functional groupsthat are not compatible with hydrogenolysis conditions, such as nitrogroups. t-Butyl ethers may be cleaved under acidic conditions using, forexample, trifluoroacetic acid.

Alternatively, the poly(oxyalkylene) aromatic ethers of formula XI maybe prepared by reacting metal salt IV with an alkylene oxide of formulaIX. The conditions for this reaction are essentially the same as thosedescribed above for the preparation of poly(oxyalkylene) alcohol VII. Ifdesired, the hydroxyl group of XI may be alkylated using well knownprocedures to provide a poly(oxyalkylene) aromatic ether of formula Iwherein R₅ is an alkyl or aralkyl group. Additionally, the hydroxylgroup of XI may be converted into a leaving group using essentially thesame procedures as those described above for the preparation of V, andthis leaving group may be displaced with the metal salt of phenol Xusing conventional procedures to provide a poly(oxyalkylene) aromaticether of formula I wherein R₅ is an alkaryl group.

The poly(oxyalkylene) aromatic ethers of the present inventioncontaining an acyl moiety, i.e., those having the formula: ##STR18##wherein A₁, R₁ -R₄, R₆, n and x are as defined above; may be preparedfrom XI by acylating the hydroxyl group of the poly(oxyalkylene) moietyof XI to form an ester.

Generally, this acylation reaction will be conducted by contacting XIwith about 0.95 to about 1.2 molar equivalents of a suitable acylatingagent. Suitable acylating agents for use in this reaction include acylhalides, such as acyl chlorides and bromides; and carboxylic acidanhydrides. Preferred acylating agents are those having the formula:

    R.sub.6 C(O)--X,

wherein R₆ is alkyl having 1 to 30 carbon atoms, phenyl, or aralkyl oralkaryl having 7 to 36 carbon atoms, and X is chloro or bromo. Morepreferably, R₆ is alkyl having 4 to 12 carbon atoms. Representativeexamples of suitable acylating agents include, but are not limited to,acetyl chloride, acetic anhydride, propionyl chloride, butanoylchloride, pivaloyl chloride, octanoyl chloride, decanoyl chloride4-t-butylbenzoyl chloride and the like.

Generally, this reaction is conducted in an inert solvent, such astoluene, dichloromethane, diethyl ether and the like, at a temperaturein the range of about 25° C. to about 150° C., and is generally completein about 0.5 to about 48 hours. When an acyl halide is employed as theacylating agent, this reaction is preferably conducted in the presenceof a sufficient amount of an amine capable of neutralizing the acidgenerated during the reaction, such as triethylamine,di(isopropyl)ethylamine, pyridine or 4-dimethylaminopyridine.

Additional methods for preparing esters from alcohols, and suitablereaction conditions for such reactions, can be found, for example, in I.T. Harrison and S. Harrison, Compendium of Organic Synthetic Methods,Vol. 1, pp. 273-276 and 280-283, Wiley-Interscience, New York (1971) andreferences cited therein.

Fuel Compositions

The poly(oxyalkylene) aromatic ethers of the present invention areuseful as additives in hydrocarbon fuels to prevent and control enginedeposits, particularly intake valve deposits. Typically, the desireddeposit control is achieved by operating an internal combustion enginewith a fuel composition containing a poly(oxyalkylene) aromatic ether ofthe present invention. The proper concentration of additive necessary toachieve the desired level of deposit control varies depending upon thetype of fuel employed, the type of engine, and the presence of otherfuel additives.

In general, the concentration of the poly(oxyalkylene) aromatic ethersof this invention in hydrocarbon fuel will

range from about 50 to about 2500 parts per million (ppm) by weight,preferably from 75 to 1,000 ppm. When other deposit control additivesare present, a lesser amount of the present additive may be used.

The poly(oxyalkylene) aromatic ethers of the present invention may alsobe formulated as a concentrate using an inert stable oleophilic (i.e.,dissolves in gasoline) organic solvent boiling in the range of about150° F. to 400° F. (about 65° C. to 205° C.). Preferably, an aliphaticor an aromatic hydrocarbon solvent is used, such as benzene, toluene,xylene or higher-boiling aromatics or aromatic thinners. Aliphaticalcohols containing about 3 to 8 carbon atoms, such as isopropanol,isobutylcarbinol, n-butanol and the like, in combination withhydrocarbon solvents are also suitable for use with the presentadditives. In the concentrate, the amount of the additive will generallyrange from about 10 to about 70 weight percent, preferably 10 to 50weight percent, more preferably from 20 to 40 weight percent.

In gasoline fuels, other fuel additives may be employed with theadditives of the present invention, including, for example, oxygenates,such as t-butyl methyl ether, antiknock agents, such asmethylcyclopentadienyl manganese tricarbonyl, and otherdispersants/detergents, such as hydrocarbyl amines, hydrocarbylpoly(oxyalkylene) amines, or succinimides. Additionally, antioxidants,metal deactivators and demulsifiers may be present.

In diesel fuels, other well-known additives can be employed, such aspour point depressants, flow improvers, cetane improvers, and the like.

A fuel-soluble, nonvolatile carrier fluid or oil may also be used withthe poly(oxyalkylene) aromatic ethers of this invention. The carrierfluid is a chemically inert hydrocarbon-soluble liquid vehicle whichsubstantially increases the nonvolatile residue (NVR), or solvent-freeliquid fraction of the fuel additive composition while notoverwhelmingly contributing to octane requirement increase. The carrierfluid may be a natural or synthetic oil, such as mineral oil, refinedpetroleum oils, synthetic polyalkanes and alkenes, includinghydrogenated and unhydrogenated polyalphaolefins, syntheticpolyoxyalkylene-derived oils, such as those described, for example, inU.S. Pat. No. 4,191,537 to Lewis, and polyesters, such as thosedescribed, for example, in U.S. Pat. Nos. 3,756,793 and 5,004,478 toRobinson and Vogel et al., respectively, and in European PatentApplication Nos. 356,726 and 382,159, published Mar. 7, 1990 and Aug.16, 1990, respectively.

These carrier fluids are believed to act as a carrier for the fueladditives of the present invention and to assist in removing andretarding deposits. The carrier fluid may also exhibit synergisticdeposit control properties when used in combination with apoly(oxyalkylene) aromatic ether of this invention.

The carrier fluids are typically employed in amounts ranging from about100 to about 5000 ppm by weight of the hydrocarbon fuel, preferably from400 to 3000 ppm of the fuel. Preferably, the ratio of carrier fluid todeposit control additive will range from about 0.5:1 to about 10:1, morepreferably from 1:1 to 4:1, most preferably about 2:1.

When employed in a fuel concentrate, carrier fluids will generally bepresent in amounts ranging from about 20 to about 60 weight percent,preferably from 30 to 50 weight percent.

EXAMPLES

The following examples are presented to illustrate specific embodimentsof the present invention and synthetic preparations thereof; andtherefore these examples should not be interpreted as limitations uponthe scope of this invention.

Example 1 Preparation ofα-(Methanesulfonyl)-ω-4-dodecylphenoxypoly(oxybutylene) ##STR19##

To a flask equipped with a magnetic stirrer, septa and a nitrogen inletwas added 244.8 grams of α-hydroxy-ω-4-dodecylphenoxypoly (oxybutylene)having an average of 19 oxybutylene units (prepared essentially asdescribed in Example 6 of U.S. Pat. No. 4,160,648), 400 mL ofdichloromethane and 26.5 mL of triethylamine. The flask was cooled in anice bath and 14.9 mL of methanesulfonyl chloride were added dropwise.The ice bath was removed and the reaction was stirred at roomtemperature for 16 hours. Dichloromethane (1.2 L) was added and theorganic phase was washed two times with saturated aqueous sodiumbicarbonate, and then once with brine. The organic layer was dried overanhydrous magnesium sulfate, filtered and concentrated in vacuo to yield265.0 grams of the desired product as a yellow oil.

Example 2 Preparation ofα-(4-Methylmercaptophenyl)-ω-4-dodecylphenoxypoly(oxybutylene) ##STR20##

To a flask equipped with a magnetic stirrer, reflux condensor, nitrogeninlet and addition funnel was added 2.5 grams of a 35 weight percentdispersion of potassium hydride in mineral oil. 4-Methylmercaptophenol(2.8 grams) dissolved in 25 mL of anhydrous tetrahydrofuran was addeddropwise and the reaction was allowed to stir at room temperature fortwo hours. The mesylate from Example 1 (33.9 grams) was dissolved in 100mL of anhydrous tetrahydrofuran and added to the reaction mixture. Theresulting mixture was refluxed for 16 hours, cooled to room temperatureand 10 mL of methanol were added. The reaction was diluted with 300 mLof diethyl ether and washed with 5% aqueous sodium hydroxide, followedby saturated aqueous sodium chloride solution. The organic layer wasthen dried over anhydrous magnesium sulfate, filtered and the solventsremoved in vacuo to yield an oil. The oil was chromatographed on silicagel, eluting with hexane/diethyl ether (1:1) to yield 30.0 grams of thedesired product as a yellow oil. The product had an average of 19oxybutylene units. ¹ H NMR (CDCl₃)δ 7.2, 6.85 (AB quartet, 4H), 7.1-7.3(m, 2H), 6.75-6.95 (m, 2H), 4.2-4.3 (m, 1H), 3.85-4.0 (m, 2H), 3.1-3.85(m, 54H), 2.4 (s, 3H), 0.6-1.8 (m, 120H).

Example 3 Preparation ofα-(4-Cyanophenyl)-ω-4-dodecylphenoxypoly(oxybutylene) ##STR21##

To a flask equipped with a magnetic stirrer, reflux condensor, nitrogeninlet and addition funnel was added 0.66 grams of an 80 weight percentdispersion of sodium hydride in mineral oil. 4-Cyanophenol (2.3 grams)dissolved in 125 mL of anhydrous N,N-dimethylformamide was addeddropwise and the reaction was allowed to stir at room temperature fortwo hours. The mesylate from Example 1 (33.9 grams) was dissolved in 25mL of anhydrous N,N-dimethylformamide and added to the reaction mixture.The resulting mixture was refluxed for 48 hours, cooled to roomtemperature and 10 mL of methanol were added. The reaction was dilutedwith 300 mL of diethyl ether and washed with 5% aqueous sodiumhydroxide, followed by saturated aqueous sodium chloride solution. Theorganic layer was then dried over anhydrous magnesium sulfate, filteredand the solvents removed in vacuo to yield 30 grams as an oil. The oilwas chromatographed on silica gel, eluting with hexane/diethyl ether(1:1) to yield 24.0 grams of the desired product as a yellow oil. Theproduct had an average of 19 oxybutylene units. ¹ H NMR (CDCl₃)δ 7.55,7.0 (AB quartet, 4H), 7.1-7.3 (m, 2H), 6.75-6.95 (m, 2H), 4.35-4.45 (m,1H), 3.85-4.0 (m, 2H), 3.1-3.85 (m, 54H), 2.35 (s, 3H), 0.6-1.8 (m,120H).

Example 4 Preparation ofα-(4-Methylsulfonylphenyl)-ω-4-dodecylphenoxypoly(oxybutylene) ##STR22##

To a flask equipped with a magnetic stirrer, thermometer and nitrogeninlet was added powdered potassium permaganate (5.0 grams) and acetone(50 mL). The contents of the flask were cooled to 0° C. andα-(4-methylmercaptophenyl)-ω-4-dodecylphenoxypoly(oxybutylene) (14.0grams, from Example 2) dissolved in 50 mL of acetone was added. Thereaction was stirred at room temperature for 16 hours, filtered and thesolvents removed in vacuo. The oil was chromatographed on silica gel,eluting with hexane/diethyl ether (1:1) to yield 14.0 grams of thedesired product as a colorless oil. The product had an average of 19oxybutylene units. ¹ H NMR (CDCl₃)δ 7.8, 7.1 (AB quartet, 4H), 7.1-7.3(m, 2H), 6.75-6.95 (m, 2H), 4.35-4.45 (m, 1H), 3.85-4.0 (m, 2H),3.1-3.85 (m, 54H), 3.0 (s, 3H), 0.6-1.8 (m, 120H).

Example 5 Single-Cylinder Engine Test

The test compounds were blended in gasoline and their deposit reducingcapacity determined in an ASTM/CFR single-cylinder engine test.

A Waukesha CFR single-cylinder engine was used. Each run was carried outfor 15 hours, at the end of which time the intake valve was removed,washed with hexane and weighed. The previously determined weight of theclean valve was subtracted from the weight of the value at the end ofthe run. The differences between the two weights is the weight of thedeposit. A lesser amount of deposit indicates a superior additive. Theoperating conditions of the test were as follows: water jackettemperature 200° F.; vacuum of 12 in Hg, air-fuel ratio of 12, ignitionspark timing of 40° BTC; engine speed is 1800 rpm; the crankcase oil isa commercial 30 W oil.

The amount of carbonaceous deposit in milligrams on the intake valves isreported for each of the test compounds in Table I.

                  TABLE I                                                         ______________________________________                                                Intake Valve Deposit Weight                                                   (in milligrams)                                                       Sample.sup.1                                                                            Run 1        Run 2   Average                                        ______________________________________                                        Base Fuel 302.6        312.2   307.4                                          Example 2  54.0         78.2    66.1                                          Example 3 124.9        165.0   145.0                                          Example 4 110.0         96.6   103.3                                          ______________________________________                                         .sup.1 At 200 parts per million actives (ppma).                          

The base fuel employed in the above single-cylinder engine tests was aregular octane unleaded gasoline containing no fuel detergent. The testcompounds were admixed with the base fuel to give a concentration of 200ppma (parts per million actives).

The data in Table I illustrates the significant reduction in intakevalve deposits provided by the poly(oxyalkylene) aromatic ethers of thepresent invention (Examples 2, 3 and 4) compared to the base fuel.

What is claimed is:
 1. A compound of the formula: ##STR23## wherein A₁is selected from the group consisting of SR^(I), SOR^(II), SO₂ R^(III),wherein R^(I), R^(II) and R^(III) are independently lower alkyl of 1 to6 carbon atoms; SO₂ NR^(IV) R^(V), wherein R^(IV) and R^(V) areindependently hydrogen, lower alkyl of 1 to 6 carbon atoms, oraminoalkyl of 1 to 6 carbon atoms, provided that R^(IV) and R^(V) maynot both be aminoalkyl; CN; and C(O)NR^(VII) R^(VIII), wherein R^(VII)and R^(VIII) are independently hydrogen, lower alkyl of 1 to 6 carbonatoms or aminoalkyl of 1 to 6 carbon atoms, provided that R^(VII) andR^(VIII) may not both by aminoalkyl;R₁ and R₂ are independentlyhydrogen, hydroxy, lower alkyl having 1 to 6 carbon atoms, or loweralkoxy having 1 to 6 carbon atoms; R₃ and R₄ are independently hydrogenor lower alkyl having 1 to 6 carbon atoms and each R₃ and R₄ isindependently selected in each --O--CHR₃ --CHR₄ -- unit; R₅ is hydrogen,alkyl having 1 to 100 carbon atoms, phenyl, aralkyl having 7 to 100carbon atoms, alkaryl having 7 to 100 carbon atoms, or an acyl grouphaving the formula: ##STR24## wherein R₆ is alkyl having 1 to 30 carbonatoms, phenyl, aralkyl having 7 to 36 carbon atoms or alkaryl having 7to 36 carbon atoms; n is an integer from 5 to 100; and x is an integerfrom 0 to
 10. 2. The compound according to claim 1, wherein n is aninteger ranging from 8 to
 50. 3. The compound according to claim 2,wherein n is an integer ranging from 10 to
 30. 4. The compound accordingto claim 2, wherein R₁ is hydrogen, hydroxy, or lower alkyl having 1 to4 carbon atoms; and R₂ is hydrogen.
 5. The compound according to claim4, wherein R₅ is hydrogen, alkyl having 1 to 30 carbon atoms, oralkylphenyl having an alkyl group containing 1 to 30 carbon atoms. 6.The compound according to claim 5, wherein R₁ is hydrogen or hydroxy. 7.The compound according to claim 6, wherein A₁ is selected from the groupconsisting of SR^(I), SO₂ R^(III), CN and C(O)NR^(VII) R^(VII).
 8. Thecompound according to claim 7, wherein R₅ is hydrogen, alkyl having 2 to24 carbon atoms, or alkylphenyl having an alkyl group containing 2 to 24carbon atoms.
 9. The compound according to claim 8, wherein one of R₃and R₄ is lower alkyl having 1 to 3 carbon atoms and the other ishydrogen.
 10. The compound according to claim 9, wherein one of R₃ andR₄ is methyl or ethyl and the other is hydrogen.
 11. The compoundaccording to claim 10, wherein x is 0, 1 or
 2. 12. The compoundaccording to claim 11, wherein R₁ is hydrogen, R₅ is alkylphenyl havingan alkyl group containing 4 to 12 carbon atoms, and x is
 0. 13. Thecompound according to claim 12, wherein A₁ is SR^(I), SO₂ R^(III) or CN.14. A fuel composition comprising a major amount of hydrocarbons boilingin the gasoline or diesel range and an effective detergent amount of acompound of the formula: ##STR25## wherein A₁ is selected from the groupconsisting of SR^(I), SOR^(II), SO₂ R^(III), wherein R^(I), R^(II) andR^(III) are independently lower alkyl of 1 to 6 carbon atoms; SO₃ H; SO₂NR^(IV) R^(V), wherein R^(IV) and R^(V) are independently hydrogen,lower alkyl of 1 to 6 carbon atoms, or aminoalkyl of 1 to 6 carbonatoms, provided that R^(IV) and R^(V) may not both be aminoalkyl; CN;CO₂ R^(VI), wherein R^(VI) is hydrogen or lower alkyl of 1 to 6 carbonatoms; and C(O)NR^(VII) R^(VIII), wherein R^(VII) and R^(VIII) areindependently hydrogen, lower alkyl of 1 to 6 carbon atoms or aminoalkylof 1 to 6 carbon atoms, provided that R^(VII) and R^(VIII) may not bothby aminoalkyl;R₁ and R₂ are independently hydrogen, hydroxy, lower alkylhaving 1 to 6 carbon atoms, or lower alkoxy having 1 to 6 carbon atoms;R₃ and R₄ are independently hydrogen or lower alkyl having 1 to 6 carbonatoms and each R₃ and R₄ is independently selected in each --O--CHR₃--CHR₄ -- unit; R₅ is hydrogen, alkyl having 1 to 100 carbon atoms,phenyl, aralkyl having 7 to 100 carbon atoms, alkaryl having 7 to 100carbon atoms, or an acyl group having the formula: ##STR26## wherein R₆is alkyl having 1 to 30 carbon atoms, phenyl, aralkyl having 7 to 36carbon atoms or alkaryl having 7 to 36 carbon atoms; n is an integerfrom 5 to 100; and x is an integer from 0 to
 10. 15. The fuelcomposition according to claim 14, wherein n is an integer ranging from8 to
 50. 16. The fuel composition according to claim 15, wherein n is aninteger ranging from 10 to
 30. 17. The fuel composition according toclaim 15, wherein R₁ is hydrogen, hydroxy, or lower alkyl having 1 to 4carbon atoms; and R₂ is hydrogen.
 18. The fuel composition according toclaim 17, wherein R₅ is hydrogen, alkyl having 1 to 30 carbon atoms, oralkylphenyl having an alkyl group containing 1 to 30 carbon atoms. 19.The fuel composition according to claim 18, wherein R₁ is hydrogen orhydroxy.
 20. The fuel composition according to claim 19, wherein A₁ isselected from the group consisting of SR^(I), SO₂ R^(III), CN, CO₂R^(VI) and C(O)NR^(VII) R^(VIII).
 21. The fuel composition according toclaim 20, wherein R₅ is hydrogen, alkyl having 2 to 24 carbon atoms, oralkylphenyl having an alkyl group containing 2 to 24 carbon atoms. 22.The fuel composition according to claim 21, wherein one of R₃ and R₄ islower alkyl having 1 to 3 carbon atoms and the other is hydrogen. 23.The fuel composition according to claim 22, wherein one of R₃ and R₄ ismethyl or ethyl and the other is hydrogen.
 24. The fuel compositionaccording to claim 23, wherein x is 0, 1 or
 2. 25. The fuel compositionaccording to claim 24, wherein R₁ is hydrogen, R₅ is alkylphenyl havingan alkyl group containing 4 to 12 carbon atoms, and x is
 0. 26. The fuelcomposition according to claim 25, wherein A₁ is SR^(I), SO₂ R^(III) orCN.
 27. The fuel composition according to claim 14, wherein saidcomposition contains about 50 to about 2500 parts per million by weightof said compound.
 28. The fuel composition according to claim 27,wherein said composition further contains about 100 to about 5000 partsper million by weight of a fuel soluble, non-volatile carrier fluid. 29.A fuel concentrate comprising an inert stable oleophilic organic solventboiling in the range of from about 150° F. to 400° F. and from about 10to about 70 weight percent of a compound of the formula: ##STR27##wherein A₁ is selected from the group consisting of SR^(I), SOR^(II),SO₂ R^(III), wherein R^(I), R^(II) and R^(III) are independently loweralkyl of 1 to 6 carbon atoms; SO₃ H; SO₂ NR^(IV) R^(V), wherein R^(IV)and R^(V) are independently hydrogen, lower alkyl of 1 to 6 carbonatoms, or aminoalkyl of 1 to 6 carbon atoms, provided that R^(IV) andR^(V) may not both be aminoalkyl; CN; CO₂ R^(VI), wherein R^(VI) ishydrogen or lower alkyl of 1 to 6 carbon atoms; and C(O)NR^(VII)R^(VIII), wherein R^(VII) and R^(VIII) are independently hydrogen, loweralkyl of 1 to 6 carbon atoms or aminoalkyl of 1 to 6 carbon atoms,provided that R^(VII) and R^(VIII) may not both by aminoalkyl;R₁ and R₂are independently hydrogen, hydroxy, lower alkyl having 1 to 6 carbonatoms, or lower alkoxy having 1 to 6 carbon atoms; R₃ and R₄ areindependently hydrogen or lower alkyl having 1 to 6 carbon atoms andeach R₃ and R₄ is independently selected in each --O--CHR₃ --CHR₄ --unit; R₅ is hydrogen, alkyl having 1 to 100 carbon atoms, phenyl,aralkyl having 7 to 100 carbon atoms, alkaryl having 7 to 100 carbonatoms, or an acyl group having the formula: ##STR28## wherein R₆ isalkyl having 1 to 30 carbon atoms, phenyl, aralkyl having 7 to 36 carbonatoms or alkaryl having 7 to 36 carbon atoms; n is an integer from 5 to100; and x is an integer from 0 to
 10. 30. The fuel concentrateaccording to claim 29, wherein n is an integer ranging from 8 to
 50. 31.The fuel concentrate according to claim 30, wherein n is an integerranging from 10 to
 30. 32. The fuel concentrate according to claim 30,wherein R₁ is hydrogen, hydroxy or lower alkyl having 1 to 4 carbonatoms; and R₂ is hydrogen.
 33. The fuel concentrate according to claim32, wherein R₅ is hydrogen, alkyl having 1 to 30 carbon atoms, oralkylphenyl having an alkyl group containing 1 to 30 carbon atoms. 34.The fuel concentrate according to claim 33, wherein R_(l) is hydrogen orhydroxy.
 35. The fuel concentrate according to claim 34, wherein A₁ isselected from the group consisting of SR^(I), SO₂ R^(III), CN, CO₂R^(VI) and C(O)NR^(VII) R^(VIII).
 36. The fuel concentrate according toclaim 35, wherein R₅ is hydrogen, alkyl having 2 to 24 carbon atoms, oralkylphenyl having an alkyl group containing 2 to 24 carbon atoms. 37.The fuel concentrate according to claim 36, wherein one of R₃ and R₄ islower alkyl having 1 to 3 carbon atoms and the other is hydrogen. 38.The fuel concentrate according to claim 37, wherein one of R₃ and R₄ ismethyl or ethyl and the other is hydrogen.
 39. The fuel concentrateaccording to claim 38, wherein x is 0, 1 or
 2. 40. The fuel concentrateaccording to claim 39, wherein R₁ is hydrogen, R₅ is alkylphenyl havingan alkyl group containing 4 to 12 carbon atoms, and x is
 0. 41. The fuelconcentrate according to claim 40, wherein A₁ is SR^(I), SO₂ R^(III) orCN.